Description
Hyland OnBase contains an unauthenticated .NET Remoting exposure in the OnBase Workflow Timer Service (Hyland.Core.Workflow.NTService.exe). An attacker who can reach the service can send crafted .NET Remoting requests to default HTTP channel endpoints on TCP/8900 (e.g., TimerServiceAPI.rem and TimerServiceEvents.rem for Workflow) to trigger unsafe object unmarshalling, enabling arbitrary file read/write. By writing attacker-controlled content into web-accessible locations or chaining with other OnBase features, this can lead to remote code execution. The same primitive can be abused by supplying a UNC path to coerce outbound NTLM authentication (SMB coercion) to an attacker-controlled host.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Hyland | OnBase Workflow Timer Service | 8.0 – ≤ 17.0.0 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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mbanyamer/CVE-2026-26221-Hyland-OnBase-Timer-Service-Unauthenticated-RCE ★ 0 · Feb 18, 2026
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://www.hyland.com/en/solutions/products/onbase product
- https://community.hyland.com/resources/bulletins-and-notices/223223-security-update-onbase-workflow-timer-service-bulletin-ob2025-03 vendor-advisory mitigation permissions-required
- https://www.vulncheck.com/advisories/hyland-onbase-timer-services-unauthenticated-net-remoting-rce third-party-advisory